Computes an approximation for a specified quartile across all row values in a column or group. Input column can be of Integer or Decimal. 
pivot
transform, the function is computed for each instance of the value specified in the group
parameter. See Pivot Transform.The approximate percentile functions utilize a different algorithm for efficiently estimating quantiles for streaming and distributed processing, depending on the running environment where the function is computed.
Tip: Approximation functions are suitable for larger datasets. As the number of rows increases, accuracy and calculation performance improves for these functions. 
Quartiles are computed as follows:
Quartile  Description 

0  Minimum value 
1  25th percentile 
2  Median value 
3  75th percentile and higher 
approximatequartile(myScores, 3) 
Output: Computes the approximate value that is at the 3rd quartile across all values in the myScores column.
approximatequartile(function_col_ref,num_quartile) [group:group_col_ref] [limit:limit_count] 
Argument  Required?  Data Type  Description 

function_col_ref  Y  string  Name of column to which to apply the function 
num_quartile  Y  integer  Integer value (03) of the quartile to compute 
dec_error_bound  N  decimal  Error factor for computing approximations. Decimal value represents error factor as a percentage (0.4 is 0.4%). 
For more information on the group
and limit
parameters, see Pivot Transform.
Name of the column the values of which you want to calculate the quartile. Column must contain Integer or Decimal values.
Required?  Data Type  Example Value 

Yes  String (column reference)  precipitationIn

Integer literal value indicating the quartile that you wish to compute. Input value must be between 0
and 3
, inclusive.
Required?  Data Type  Example Value 

Yes  Integer  3 
As needed, you can insert an error boundary factor as a parameter into the computation of this approximate value.
NOTE: This value is not applicable to jobs executed on the running environment. 
0.5
(0.5%). Required?  Data Type  Example Value 

No  Decimal (literal)  0.01
